Subjects were recruited through advertisements from October 2004 until April 2005. Recruitment of 320 subjects (140 from Iceland, 120 from Spain, and 60 from Ireland). The inclusion criteria were body mass index (BMI) 27.5 to 32.5 kg/m2, age 20-40 years, and a waist circumference of equal or more than 94 cm and 80 cm for men and women, respectively. Exclusion criteria were weight change due to weight loss diet within 3 months before the start of the study, use of supplements giving n-3 fatty acids, calcium or vitamin-D during the last three months, drug treatment of diabetes mellitus, hypertension or hyperlipidemia and women’s pregnancy or lactation. Each subject was instructed to follow a diet, energy-restricted by 30% from estimated energy expenditure (approximately 600 kcal/day), for 8 consecutive weeks. The subjects were randomly assigned to four diets varying in types of dietary protein and amount of n-3 fatty acids (especially very long chain n-3 fatty acids):